A method for detecting paths and amount of loss of desulfurization organic components in a flue gas desulfurization system includes preparing a to-be-measured solution and a base standard solution, and diluting the base standard solution with water to a plurality of standard solutions containing different concentrations of desulfurization organic components; adjusting the to-be-measured solution and standard solutions to have a strong acidity, respectively, such that each of desulfurization organic components in the to-be-measured solution and standard solutions exists in ion forms; heating and oscillating the to-be-measured solution and standard solutions, respectively; respectively detecting carbon elements in the standard solutions, to form a linear relationship between concentrations of the desulfurization organic components in the standard solutions and detected carbon element data; and detecting carbon elements in the to-be-measured solution, and obtaining a total concentration of the desulfurization organic components in the to-be-measured solution according to the linear relationship.